The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Air is drawn into an engine through an intake manifold. A throttle valve controls airflow into the engine. The air mixes with fuel from one or more fuel injectors to form an air/fuel mixture. The air/fuel mixture is combusted within one or more cylinders of the engine. Combustion of the air/fuel mixture may be initiated by, for example, injection of the fuel or spark provided by a spark plug.
An engine control module (ECM) controls the torque output of the engine. Under some circumstances, the ECM may operate the engine in one or more modes that increase efficiency (i.e., reduce fuel consumption). For example only, the ECM may disable one or more cylinders of the engine and/or operate non-disabled cylinders of the engine in a homogenous charge compression ignition (HCCI) mode.